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MQUEUEFS(5) FreeBSD File Formats Manual MQUEUEFS(5)
NAMEmqueuefs -- POSIX message queue file system
SYNOPSIS
To link into kernel:
optionsP1003_1B_MQUEUE
To load as a kernel loadable module:
kldload mqueuefs
DESCRIPTION
The mqueuefs module will permit the FreeBSD kernel to support POSIX mes-
sage queue. The module contains system calls to manipulate POSIX message
queues. It also contains a file system to implement a view for all mes-
sage queues of the system. This helps users to keep track of their mes-
sage queues and make it more easily usable without having to invent addi-
tional tools.
The most common usage is as follows:
mount -t mqueuefs null /mnt/mqueue
where /mnt/mqueue is a mount point.
It is possible to define an entry in /etc/fstab that looks similar to:
null /mnt/mqueue mqueuefs rw 0 0
This will mount mqueuefs at the /mnt/mqueue mount point during system
boot. Using /mnt/mqueue as a permanent mount point is not advised as its
intention has always been to be a temporary mount point. See hier(7) for
more information on FreeBSD directory layout.
Some common tools can be used on the file system, e.g.: cat(1), chmod(1),
chown(8), ls(1), rm(1), etc. To use only the message queue system calls,
it is not necessary for user to mount the file system, just load the mod-
ule or compile it into the kernel. Manually creating a file, for exam-
ple, ``touch /mnt/mqueue/myqueue'', will create a message queue named
myqueue in the kernel, default message queue attributes will be applied
to the queue. It is not advised to use this method to create a queue; it
is better to use the mq_open(2) system call to create a queue as it
allows the user to specify different attributes.
To see the queue's attributes, just read the file:
cat /mnt/mqueue/myqueue
SEE ALSOmq_open(2), nmount(2), unmount(2), mount(8), umount(8)AUTHORS
This manual page was written by David Xu <davidxu@FreeBSD.org>.
FreeBSD 10.1 November 30, 2005 FreeBSD 10.1